package net.melon.plugin.core.interceptor;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import net.melon.plugin.core.aware.FileUploadAware;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
import org.apache.struts2.interceptor.FileUploadInterceptor;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionProxy;
import com.opensymphony.xwork2.ValidationAware;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.opensymphony.xwork2.util.LocalizedTextUtil;
import com.opensymphony.xwork2.util.PatternMatcher;
import com.opensymphony.xwork2.util.TextParseUtil;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

public class PerfFileUploadInterceptor extends AbstractInterceptor {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = -5698809917642357461L;
	
	protected boolean useActionMessageBundle = true;
	
	protected static final Logger LOG = LoggerFactory.getLogger(FileUploadInterceptor.class);
    private static final String DEFAULT_MESSAGE = "no.message.found";

	protected Long maximumSize;
    protected Set<String> allowedTypesSet = Collections.emptySet();
    protected Set<String> allowedExtensionsSet = Collections.emptySet();
	
    private PatternMatcher matcher;
    
	@Override
	public String intercept(ActionInvocation invocation) throws Exception {
		if(invocation.getAction() instanceof FileUploadAware){
			
			FileUploadAware fuaware = (FileUploadAware) invocation.getAction();
			setMaximumSize(fuaware.getMaximumSize());
			setAllowedExtensions(fuaware.getAllowedExtensionsSet());
			setAllowedTypes(fuaware.getAllowedTypesSet());
			
			ActionContext ac = invocation.getInvocationContext();

	        HttpServletRequest request = (HttpServletRequest) ac.get(ServletActionContext.HTTP_REQUEST);

	        if (!(request instanceof MultiPartRequestWrapper)) {
	            if (LOG.isDebugEnabled()) {
	                ActionProxy proxy = invocation.getProxy();
	                LOG.debug(getTextMessage("struts.messages.bypass.request", new Object[]{proxy.getNamespace(), proxy.getActionName()}, ac.getLocale()));
	            }

	            return invocation.invoke();
	        }

	        ValidationAware validation = null;

	        Object action = invocation.getAction();

	        if (action instanceof ValidationAware) {
	            validation = (ValidationAware) action;
	        }

	        MultiPartRequestWrapper multiWrapper = (MultiPartRequestWrapper) request;

	        if (multiWrapper.hasErrors()) {
	            for (String error : multiWrapper.getErrors()) {
	                if (validation != null) {
	                    validation.addActionError(error);
	                }

	                LOG.warn(error);
	            }
	        }

	        // bind allowed Files
	        Enumeration fileParameterNames = multiWrapper.getFileParameterNames();
	        while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
	            // get the value of this input tag
	            String inputName = (String) fileParameterNames.nextElement();

	            // get the content type
	            String[] contentType = multiWrapper.getContentTypes(inputName);

	            if (isNonEmpty(contentType)) {
	                // get the name of the file from the input tag
	                String[] fileName = multiWrapper.getFileNames(inputName);

	                if (isNonEmpty(fileName)) {
	                    // get a File object for the uploaded File
	                    File[] files = multiWrapper.getFiles(inputName);
	                    if (files != null && files.length > 0) {
	                        List<File> acceptedFiles = new ArrayList<File>(files.length);
	                        List<String> acceptedContentTypes = new ArrayList<String>(files.length);
	                        List<String> acceptedFileNames = new ArrayList<String>(files.length);
	                        String contentTypeName = inputName + "ContentType";
	                        String fileNameName = inputName + "FileName";

	                        for (int index = 0; index < files.length; index++) {
	                            if (acceptFile(action, files[index], fileName[index], contentType[index], inputName, validation, ac.getLocale())) {
	                                acceptedFiles.add(files[index]);
	                                acceptedContentTypes.add(contentType[index]);
	                                acceptedFileNames.add(fileName[index]);
	                            }
	                            /*else{
	                            	throw new MelonException("struts.messages.file.upload.error");
	                            }*/
	                        }

	                        if (!acceptedFiles.isEmpty()) {
	                            Map<String, Object> params = ac.getParameters();

	                            params.put(inputName, acceptedFiles.toArray(new File[acceptedFiles.size()]));
	                            params.put(contentTypeName, acceptedContentTypes.toArray(new String[acceptedContentTypes.size()]));
	                            params.put(fileNameName, acceptedFileNames.toArray(new String[acceptedFileNames.size()]));
	                        }
	                    }
	                } else {
	                    LOG.warn(getTextMessage(action, "struts.messages.invalid.file", new Object[]{inputName}, ac.getLocale()));
	                }
	            } else {
	                LOG.warn(getTextMessage(action, "struts.messages.invalid.content.type", new Object[]{inputName}, ac.getLocale()));
	            }
	        }
	        // invoke action
	        return invocation.invoke();
		}else{
			return invocation.invoke();
		}
	}

	/**
     * Override for added functionality. Checks if the proposed file is acceptable based on contentType and size.
     *
     * @param action      - uploading action for message retrieval.
     * @param file        - proposed upload file.
     * @param contentType - contentType of the file.
     * @param inputName   - inputName of the file.
     * @param validation  - Non-null ValidationAware if the action implements ValidationAware, allowing for better
     *                    logging.
     * @param locale
     * @return true if the proposed file is acceptable by contentType and size.
     */
    protected boolean acceptFile(Object action, File file, String filename, String contentType, String inputName, ValidationAware validation, Locale locale) {
        boolean fileIsAcceptable = false;

        // If it's null the upload failed
        if (file == null) {
            String errMsg = getTextMessage(action, "struts.messages.error.uploading", new Object[]{inputName}, locale);
            if (validation != null) {
                validation.addFieldError(inputName, errMsg);
            }

            LOG.warn(errMsg);
        } else if (maximumSize != null && maximumSize < file.length()) {
            String errMsg = getTextMessage(action, "struts.messages.error.file.too.large", new Object[]{inputName, filename, file.getName(), "" + file.length()}, locale);
            if (validation != null) {
                validation.addFieldError(inputName, errMsg);
            }

            LOG.warn(errMsg);
        } else if ((!allowedTypesSet.isEmpty()) && (!containsItem(allowedTypesSet, contentType))) {
            String errMsg = getTextMessage(action, "struts.messages.error.content.type.not.allowed", new Object[]{inputName, filename, file.getName(), contentType}, locale);
            if (validation != null) {
                validation.addFieldError(inputName, errMsg);
            }

            LOG.warn(errMsg);
        } else if ((!allowedExtensionsSet.isEmpty()) && (!hasAllowedExtension(allowedExtensionsSet, filename))) {
            String errMsg = getTextMessage(action, "struts.messages.error.file.extension.not.allowed", new Object[]{inputName, filename, file.getName(), contentType}, locale);
            if (validation != null) {
                validation.addFieldError(inputName, errMsg);
            }

            LOG.warn(errMsg);
        } else {
            fileIsAcceptable = true;
        }

        return fileIsAcceptable;
    }

    /**
     * @param extensionCollection - Collection of extensions (all lowercase).
     * @param filename            - filename to check.
     * @return true if the filename has an allowed extension, false otherwise.
     */
    private boolean hasAllowedExtension(Collection<String> extensionCollection, String filename) {
        if (filename == null) {
            return false;
        }

        String lowercaseFilename = filename.toLowerCase();
        for (String extension : extensionCollection) {
            if (lowercaseFilename.endsWith(extension)) {
                return true;
            }
        }

        return false;
    }

    /**
     * @param itemCollection - Collection of string items (all lowercase).
     * @param item           - Item to search for.
     * @return true if itemCollection contains the item, false otherwise.
     */
    private boolean containsItem(Collection<String> itemCollection, String item) {
        for (String pattern : itemCollection)
            if (matchesWildcard(pattern, item))
                return true;
        return false;
    }

    private boolean matchesWildcard(String pattern, String text) {
        Object o = matcher.compilePattern(pattern);
        return matcher.match(new HashMap<String, String>(), text, o);
    }

    private boolean isNonEmpty(Object[] objArray) {
        boolean result = false;
        for (int index = 0; index < objArray.length && !result; index++) {
            if (objArray[index] != null) {
                result = true;
            }
        }
        return result;
    }

    private String getTextMessage(String messageKey, Object[] args, Locale locale) {
        return getTextMessage(null, messageKey, args, locale);
    }

    private String getTextMessage(Object action, String messageKey, Object[] args, Locale locale) {
        if (args == null || args.length == 0) {
            if (action != null && useActionMessageBundle) {
                return LocalizedTextUtil.findText(action.getClass(), messageKey, locale);
            }
            return LocalizedTextUtil.findText(this.getClass(), messageKey, locale);
        } else {
            if (action != null && useActionMessageBundle) {
                return LocalizedTextUtil.findText(action.getClass(), messageKey, locale, DEFAULT_MESSAGE, args);
            }
            return LocalizedTextUtil.findText(this.getClass(), messageKey, locale, DEFAULT_MESSAGE, args);
        }
    }
    
    @Inject
    public void setMatcher(PatternMatcher matcher) {
        this.matcher = matcher;
    }

//    public void setUseActionMessageBundle(String value) {
//        this.useActionMessageBundle = Boolean.valueOf(value);
//    }

    /**
     * Sets the allowed extensions
     *
     * @param allowedExtensions A comma-delimited list of extensions
     */
    public void setAllowedExtensions(String allowedExtensions) {
        allowedExtensionsSet = TextParseUtil.commaDelimitedStringToSet(allowedExtensions);
    }

    /**
     * Sets the allowed mimetypes
     *
     * @param allowedTypes A comma-delimited list of types
     */
    public void setAllowedTypes(String allowedTypes) {
        allowedTypesSet = TextParseUtil.commaDelimitedStringToSet(allowedTypes);
    }

    /**
     * Sets the maximum size of an uploaded file
     *
     * @param maximumSize The maximum size in bytes
     */
    public void setMaximumSize(Long maximumSize) {
        this.maximumSize = maximumSize;
    }
}
